1. Field of the Invention
The present invention relates to a digital camera which shortens processing time for correcting distortion.
2. Background Arts
A digital camera converts an optical image of a subject photographed by a CCD and the like into digital image data, which is recorded on a recording medium such as an internal memory or a memory card. Recently, the digital camera that adopts zoom function is preferred. Since an optical zoom is superior to a digital zoom in terms of image quality and response speed, a digital camera with a zoom lens is widely used.
To miniaturize the digital camera, a small and thin zoom lens is effectively adopted. An optical image photographed by this type of zoom lens, however, tends to distort severely. Generally, the photographed image distorts in a barrel shape, as illustrated in solid lines in FIG. 4A, when the zoom lens is on the wide-angle side. When the zoom lens is on the telephoto side, on the other hand, the photographed image distorts in a pincushion shape, as shown in FIG. 4B.
Japanese Patent Laid-Open Publication No. 2000-3437 discloses a method for correcting distortion by use of an image processing system such as a personal computer after photography. Japanese Patent Laid-Open Publication No. 2001-5956 discloses a digital camera which corrects distortion in image processing inside the camera.
The above digital camera carries out distortion correction processes for each of the barrel distortion on the wide-angle side and the pincushion distortion on the telephoto side. Thus, the processing time for distortion correction becomes long. When the digital camera carries out the process to correct the distortion inside the digital camera, long processing time adversely affects reduction in the time interval between exposures.